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authorPeter Malone <peter.malone@gmail.com>2018-03-07 14:00:34 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-30 07:50:35 +0200
commit05b4268070b14dbd77ac6f5986b77a80a458fffa (patch)
tree601944fe16b5974875c88a9644e0d0d79727f24a
parentd2d48e0161b54be303b8023fd85b4c95ac8b83ca (diff)
fbdev: Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper().
[ Upstream commit 250c6c49e3b68756b14983c076183568636e2bde ] Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper(). 'index' is defined as an int in sbusfb_ioctl_helper(). We retrieve this from the user: if (get_user(index, &c->index) || __get_user(count, &c->count) || __get_user(ured, &c->red) || __get_user(ugreen, &c->green) || __get_user(ublue, &c->blue)) return -EFAULT; and then we use 'index' in the following way: red = cmap->red[index + i] >> 8; green = cmap->green[index + i] >> 8; blue = cmap->blue[index + i] >> 8; This is a classic information leak vulnerability. 'index' should be an unsigned int, given its usage above. This patch is straight-forward; it changes 'index' to unsigned int in two switch-cases: FBIOGETCMAP_SPARC && FBIOPUTCMAP_SPARC. This patch fixes CVE-2018-6412. Signed-off-by: Peter Malone <peter.malone@gmail.com> Acked-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/video/fbdev/sbuslib.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c
index a350209ffbd3..31c301d6be62 100644
--- a/drivers/video/fbdev/sbuslib.c
+++ b/drivers/video/fbdev/sbuslib.c
@@ -121,7 +121,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg,
unsigned char __user *ured;
unsigned char __user *ugreen;
unsigned char __user *ublue;
- int index, count, i;
+ unsigned int index, count, i;
if (get_user(index, &c->index) ||
__get_user(count, &c->count) ||
@@ -160,7 +160,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg,
unsigned char __user *ugreen;
unsigned char __user *ublue;
struct fb_cmap *cmap = &info->cmap;
- int index, count, i;
+ unsigned int index, count, i;
u8 red, green, blue;
if (get_user(index, &c->index) ||